1. Field of the Invention
The present invention relates to a method of fabricating a semiconductor substrate and a method of recycling a heterogeneous substrate during fabrication of said semiconductor substrate.
2. Description of the Prior Art
Semiconductor light-emitting devices, such as light-emitting diodes, can be used for a wide variety of devices, e.g. optical displaying devices, traffic lights, communication devices, and illumination devices.
Up to now, a semiconductor light-emitting device is mainly grown on a sapphire substrate. The sapphire substrate is made by cutting a sapphire ingot, and the sapphire ingot is formed by a crystal pulling process. However, the crystal pulling process wastes time and costs much. As a result, if the substrate used for the fabrication of the semiconductor light-emitting device can be formed by other more efficient growing processes (e.g. an epitaxy process), then it can overcome the traditional problem in producing sapphire substrates.
On the other hand, as mentioned above, the current semiconductor light-emitting device is mainly formed on a sapphire substrate. However, it may lead to the shortage of the sapphire substrate. As a result, if the sapphire substrate can be recycled during the fabrication of the semiconductor optoelectronic device, then the sapphire substrate can be utilized again to reduce manufacture cost.
In the prior art, a semiconductor light-emitting device can be illuminated by a laser, and a lift-off layer of said semiconductor light-emitting device can be decomposed by absorbing the energy of the laser such that the substrate of the semiconductor light-emitting device can be debonded away from the semiconductor light-emitting device. However, this method costs much and is unfavorable in practical applications.
Therefore, to solve the aforementioned problem, the main scope of the invention is to provide a method of fabricating a first substrate and a method of recycling a second substrate during fabrication of the first substrate.